Cyclic performance tests and numerical analysis of prefabricated CFS shear walls filled with lightweight EPS mortars

Abstract

With the advancement and promotion of green buildings, infilled cold-formed steel (CFS) shear walls have gained considerable attention. In order to promote the assembly degree, novel prefabricated CFS shear walls filled with lightweight expanded polystyrene (EPS) mortars is developed and their corresponding connection method are also developed in this paper. Then, integral prefabricated lightweight EPS mortars (LEM)-filled CFS shear wall and four spliced shear walls assembled using three separated shear walls were designed and tested to evaluate their cyclic performance. The failure patterns, load–displacement relationships, feature values, ductility, stiffness and energy dissipation were systematically analyzed and asserted. The results indicated that prefabricated LEM-filled shear wall appeared superior cyclic performance and spliced shear wall could be used in engineering practice to improve the standardization produce. Subsequently, three-dimensional finite element (FE) models of prefabricated LEM-filled CFS shear walls were established and verified by the experimental data. The FE models considered the initial imperfection of wall studs, nonlinear behavior of the self-drilling screws, and the assembling of separated shear walls. Moreover, the contact stress distributions between the CFS components and LEMs were also analyzed. Finally, a simplified model considering the assembly feature was proposed to predict the shear bearing capacity of the prefabricated shear wall. The exploration illustrated that enhancing the connections between the separated shear walls is an effective measure to guarantee the wall strength. The test and analytical results provide guidance for the application of prefabricated LEM-filled CFS shear walls and promote their development.